Brian Delmonaco, MD
Good Samaritan Regional Medical Center
Corvallis, Oregon
Disclosure information not submitted.
William Cheung, MD
Nephrologist
Samaritan Health Services, United States
Disclosure information not submitted.
Hahn Duong, MD
Internal Medicine Resident PGY1
Samaritan Health Services, United States
Disclosure information not submitted.
Ryan Gienapp, DO
Internal Medicine Resident PGY2
Samaritan Health Services, United States
Disclosure information not submitted.
Title: Seraph-100 Microbind Filter with Citrate in COVID-19 Critical Illness: A Case Series
Introduction: The Seraph-100 Microbind Affinity Blood Filter (ExThera Medical Corporation, Martinez, CA, USA) provides an artificial glycocalyx consisting of heparin bound to polyethylene beads. By way of extracorporeal blood purification (ECBP), the Seraph reduces serum SARS-CoV-2 viral load and may lower mortality from COVID-19. The mortality rate for intubated COVID-19 patients approaches 88 percent. The COSA registry's interim analysis demonstrated 27% mortality in patients treated with Seraph. The PURIFY-OBS trial demonstrated a lower mortality with Seraph (37.7%) compared to historical controls (67.4%). ECBP circuits clot (13-20% failure rate) despite anticoagulation with heparin. The addition of regional citrate to the ECBP circuit reduces circuit failure though exposes patients to potentially unnecessary dialysis.
Methods: We present a case series of 6 patients who underwent ECBP with the Seraph device who clotted circuits. To overcome circuit clotting, anticoagulation with regional heparin, systemic anticoagulation, or both systemic anticoagulation and regional citrate were used. We review the lessons learned at a community hospital to prevent clotting of the ECBP circuit and the outcomes of patients who had no indication for hemodialysis prior to exposure to ECBP with regional citrate.
Results: Six patients with COVID-19, who had a P:F ratio < 150, were intubated and underwent ECBP for 24-hours with the Seraph filter. Five of the 6 patients received ECBP at 200mL/hr. One patient died before the completion of ECBP. Of the 5 survivors, all clotted multiple circuits. When regional anticoagulation with citrate was added to systemic heparin, 2 patients completed uninterrupted ECBP without further circuit failure. The patients who were placed on citrated ECBP circuits had similar creatinine and urine output pre ECBP and 72-hours post ECBP.
Conclusions: The treatment of patients critically ill from COVID-19 with the Seraph filter, when dosed with regional citrate to prevent clotting of the ECBP circuit, showed no renal complications, was successful, and is achievable at a community hospital.